Reverting 3174. Aka reapplying 3150, 3151 and 3159. Aka api accessor

src/arm/frames-arm.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 36 matching lines @@
   Object* marker = Memory::Object_at(state->fp + offset);
   if (!marker->IsSmi()) return JAVA_SCRIPT;
   return static_cast<StackFrame::Type>(Smi::cast(marker)->value());
 }
 
 
 StackFrame::Type ExitFrame::GetStateForFramePointer(Address fp, State* state) {
   if (fp == 0) return NONE;
   // Compute frame type and stack pointer.
   Address sp = fp + ExitFrameConstants::kSPDisplacement;
-  Type type;
-  if (Memory::Address_at(fp + ExitFrameConstants::kDebugMarkOffset) != 0) {
-    type = EXIT_DEBUG;
+  const int offset = ExitFrameConstants::kCodeOffset;
+  Object* code = Memory::Object_at(fp + offset);
+  bool is_debug_exit = code->IsSmi();
+  if (is_debug_exit) {
     sp -= kNumJSCallerSaved * kPointerSize;
-  } else {
-    type = EXIT;
   }
   // Fill in the state.
   state->sp = sp;
   state->fp = fp;
   state->pc_address = reinterpret_cast<Address*>(sp - 1 * kPointerSize);
-  return type;
+  return EXIT;
 }
 
 
 void ExitFrame::Iterate(ObjectVisitor* v) const {
-  // Do nothing
+  v->VisitPointer(&code_slot());
+  // The arguments are traversed as part of the expression stack of
+  // the calling frame.
 }
 
 
 int JavaScriptFrame::GetProvidedParametersCount() const {
   return ComputeParametersCount();
 }
 
 
 Address JavaScriptFrame::GetCallerStackPointer() const {
   int arguments;
@@ skipping 25 matching lines @@
 
 
 Address InternalFrame::GetCallerStackPointer() const {
   // Internal frames have no arguments. The stack pointer of the
   // caller is at a fixed offset from the frame pointer.
   return fp() + StandardFrameConstants::kCallerSPOffset;
 }
 
 
 } }  // namespace v8::internal